Power generation, particularly for use with motive applications such as vehicles of various sorts, is constantly in need of improvements to power density (i.e. power to weight ratio), not to mention increased reliability and smaller envelopes, to name but a few concerns. But these demands tend to be at odds with one another. The inclusion of multiple motor/generators provides higher reliability, but increases weight and the on-board envelope required. Increasing the driving speed of generators, in particular, can increase the generated power density (more power, less space and weight), but higher-speed applications tend to have more complicated dynamics and rotor balancing issues, and the problems are further compounded if a plurality of such machines are provided.